Show Date: December 14, 2005  
Pam Eastlick for THE DEEP on line

LOOKING UP
AND
WASTING FISH

Greetings and welcome to The Deep column and the deepest radio show on Earth. The Deep is the science talk radio program that takes you from the depths of the ocean to the farthest reaches of the universe. This week on The Deep, aired at 6:00 this evening on K-57, we’ll talk about space images and how to make them. Then we’ll have some expedition calls. We hope to hear from the Oceana expedition ship, the Ranger. We’ll also have some science news updates and we’ll be taking your phone calls. Tune in tonight and join host Jim Sullivan, Pam Eastlick and our expedition coordinator Peter Melyan for the latest in scientific news! Then log on to www.thedeepradioshow.com for more information on all the latest and deepest news!

MAKING PICTURES
We’ve looked at the night sky since we lived in caves and for most of human history, it was pretty much a study in black and white. Mars and some stars like Betelgeuse and Aldebaran are noticeably red and other stars are definitely blue but still, black and white pretty much described it.

Then, in 1610, Galileo looked at the sky for the first time with a telescope and discovered that not only was Mars red, Saturn was a deep golden yellow and Jupiter had colored stripes. Perhaps the sky wasn’t just black and white after all.
As telescopes improved, astronomers began to find fuzzy things in the sky that definitely weren’t stars and weren’t planets and weren’t comets. Since there were healthy prizes for finding new comets, it became worth your while if you were a serious astronomer to have a list of those fuzzy blobs and their locations so you didn’t report them as comets and embarrass yourself.

It took many years before telescopes improved to the point that we learned just what these fuzzy objects were. Many of them were called ‘planetary nebula’ (nebula is the Latin word for ‘fuzzy object), because in the small telescopes of the day, they looked like stars with planets around them.

In the 1930’s, Edwin Hubble, the astronomer for whom the Hubble Space Telescope is named, discovered that many of these ‘fuzzy spots’ were, in fact, gigantic star cities; galaxies like our own Milky Way. But others were not galaxies and the larger telescopes of the last century revealed many of them were an astounding rosy red.

Each element in the periodic table produces a characteristic color when it’s converted to a gas. This is the basis of spectroscopy, the science that allows astronomers to determine the elements a star contains, just by looking at its light.
Most of the nebulae scattered around the sky were that amazing rosy red because that’s the color produced by ionized hydrogen. Ninety percent of all atoms are hydrogen and rosy red is the favorite color of the universe.

Most early sky photos were black and white because early photographic films recorded only black and white. These photographs can be things of beauty in their own right, but with the development of color films, sky images began to take on a completely new dimension.

But interestingly enough, modern space photography has gone right back to black and white. Most big telescopes (including the Hubble Space Telescope) don’t use color film — in fact, they doesn't use film at all. Their cameras record light from the universe with special electronic detectors called CCDs. These detectors produce images of the cosmos not in color, but in shades of black and white.

Taking color pictures with CCDs is much more complex than taking color pictures with a traditional camera. Finished color images are actually combinations of two or more black-and-white exposures with the color added during image processing. Scientists often use color as a tool, sometimes to enhance an object's detail or to see processes that ordinarily can’t be seen by human eyes.

Energy from astronomical objects comes in a wide range of frequencies. Humans see only the very narrow range of frequencies called visible light. CCD-equipped telescopes can detect all the visible wavelengths of light plus others that are invisible to human eyes, like ultraviolet and infrared light.

Astronomical objects look much different when viewed in different light wavelengths. CCD-equipped telescopes use special filters that allow only a certain range of light wavelengths through. Once the unwanted light is filtered out, the remaining light is recorded.

Most CCD cameras have many filters that allow them to record images in a variety of wavelengths. Since the cameras can detect light outside the visible light spectrum, the use of filters allows scientists to see "invisible" features of objects — those only visible in ultraviolet and infrared wavelengths.

Many full-color CCD images are combinations of three separate exposures — one each taken in red, green, and blue light. When mixed together, these three colors of light can simulate almost any color of light that is visible to human eyes. Televisions, computer monitors, and video cameras recreate colors in the same way.

Some space images have colors assigned to different elements, like hydrogen, oxygen and nitrogen, while others have colors assigned to different temperatures. Some images approximate reality – their colors assigned to make an object appear as it would if you saw it through the window of a spaceship, while other images bear no relation to the object’s actual appearance.

Just remember that the next time you see an astounding space image that creating color images from the original black-and-white exposures is equal parts art and science.

Taking pictures of an object in many different wavelengths can tell you a great deal about the object.

Visible Light This is a picture of the galaxy Centaurus A taken in visible light. If we were a little closer to this galaxy than 13 million light years, it would look like this in our sky.

Ultraviolet This picture shows you how Centaurus A looks in ultraviolet. It tells you that many of the stars of Centaurus A are like our own Sun and shine more brightly in visible light than in the hotter temperatures of ultraviolet.

X-ray This picture taken by the Chandra space telescope shows how this massive galaxy would appear if you were Superman. This is Centaurus A in X-rays. And no, the newspaper didn’t change the orientation. Astronomers study Centaurus A because it’s an active galaxy. There’s something going on at its core that’s sending huge fountains of X-rays into space at right angles to the rest of the galaxy.

And the galaxy isn’t just sending up fountains of X-rays. This picture shows Centaurus in radio waves. And what’s causing those huge fountains of radio and X-rays? Astronomers are still debating the issue, but most agree that Centaurus A harbors a monstrous black hole at its core. And we would never have known from looking at the galaxy in visible light.

For more great pictures of space objects at different wavelengths, surf on over to the Cool Cosmos site. Then join us tonight on The Deep as we discuss astrophotography and the wonderful science done not with mirrors, but with pictures.

WASTING AWAY
One of our frequent expedition calls is the Ranger, a research vessel operated by the Oceana group of scientists, researchers and environmentalists. Oceana has commissioned a scientific study of commercial fisheries in the United States and discovered that for every five pounds of fish caught by U.S. commercial fisheries, one pound is dumped – dead, dying and wasted. Each year, U.S. commercial fishing operations throw away more than one million metric tons of fish. The Gulf of Mexico shrimp fishery ranked worst of all, discarding more than 472,000 metric tons, or one billion pounds of fish, nearly half of the total waste in U.S. fisheries.

The study also found that trawl fisheries overwhelmingly account for the discards in U.S. fisheries. The shrimp and fish trawl fisheries are responsible for 78 percent of all discards in U.S. fisheries. The study lists the 12 worst fisheries for discards by weight and by ratio of discards to landings, and most are trawl fisheries that target fish that live on or near the ocean bottom.

The study was conducted using the most recent data publicly available for all federally managed fisheries in the United States. The findings are based on data for 2002 and 2003, with the exception of the Atlantic highly migratory species fishery, for which the most recent available data is from 2001.

“This study demonstrates that the United States is as bad as – or worse than – the rest of the world’s top fishing nations when it comes to waste,” said Dr. Michael Hirshfield, chief scientist and senior vice president for Oceana. “The United States needs to clean up its act and stop this dirty fishing, as it is required to do by laws passed more than a decade ago.”

So how do these wasteful practices impact the world’s oceans? We hope to hear from the Ranger about this and other ocean news.

Whether we’re learning about space images or wasteful practices in the commercial fishing industry, The Deep, hosted by Jim Sullivan with Pam Eastlick and Peter Melyan is the place to be on K-57 tonight at 6:00 p.m. Don’t miss it!